This specification relates generally to information systems, and more particularly to interactive searching.
Users seeking to find information among an abundance of data can turn to an information retrieval system that can search for the sought after information. A search engine is an example of an information retrieval system that can be used to find information on the World Wide Web. To find information, users can specify search criteria (a “query”) to a user interface provided by the search engine.
Typical general-purpose search engines provide a user interface that allows search queries to be specified as simple strings of text. A query is typically answered with an overwhelming number of search result items. Search result items can refer to a wide variety of content, pertain to various subjects, and may or may not reflect the sort of information that a user is actually seeking. For example, a user seeking a recipe for Cajun jambalaya may provide the query “Cajun” and receive search results concerning Cajun cuisine, Acadian history, and performance art in Louisiana. Finding precise information from among the search results can be difficult. To refine the search results, users are normally required to revise their search criteria. Typically, users' lack of knowledge prevents them from providing the precise terminology needed to accurately articulate the specific search results that they desire.
Search engines that pertain to particular subject matter may provide a user interface that allows users to provide subject-specific search criteria that are germane to the search engine's subject matter. Ideally, the user interface of the search engine provides some guidance for users by providing subject-specific search options that users might otherwise be unaware of. For example, a real-estate searching facility might allow specification of criteria such as geographical location, minimum and maximum price, and whether or not the property has a swimming pool. For users, switching between various subject-specific search engines can be inconvenient and awkward. Subject-specific search engines typically do not provide users with a comprehensive overview that encompasses more than one subject.